Consumption is a major concept in economics and is also studied by many other social sciences. Economists are particularly interested in the relationship between consumption and income, as modeled with the consumption function.
Consumption is defined in part by comparison to production. In the tradition of the Columbia School of Household Economics also known as the New Home Economics commercial consumption has to be analyzed in the context of household production. The opportunity cost of time affects the cost of home-produced substitutes and therefore demand for commercial goods and services. The elasticity of demand for consumption goods is also a function of who performs chores in households and how their spouses compensate them for opportunity costs of home production.
Aggregate consumption is a component of aggregate demand. According to the UN, "today’s consumption is undermining the environmental resource base. It is exacerbating inequalities. And the dynamics of the consumption-poverty-inequality-environment nexus are accelerating. If the trends continue without change — not redistributing from high-income to low-income consumers, not shifting from polluting to cleaner goods and production technologies, not shifting priority from consumption for conspicuous display to meeting basic needs — today’s problems of consumption and human development will worsen." Developing countries like India, as they move down the path of copying the consumption patterns of developed economies, will basically create demands that earth will not be able to fulfill. Some economists[who?] talk about putting a price on using earth's resources which is in addition to the cost of just extracting them.